Humanure Composting

by Joel ForgeNovember 29, 2011

After my book review on Surviving in the Suburbs I got some questions emailed about the specifics behind the septic tank comment. So here are some of my thoughts on the matter, in a bit more detail than what was covered in the book. I should note, I’ve not done any humanure composting. I’ve read a lot about it, and I practice a lot of the components, but at the end of the day 95% of my waste gets flushed down the toilet into a nice efficient waste water treatment plant.

Compost – In a grid down situation, the ability to flush away human waste is usually gone. Without proper treatment it can quickly become a hazard to your family’s health. In most situations the best thing to do is to compost the waste. Humanure composting follows the basic principles of organic composting. Make a big pile, keep the carbon and nitrogen balanced, let it cook itself down and then use it to boost soil fertility. The comment made in Surviving the Suburbs mentioned that people with septic systems could probably continue to use them, with modifications. The modifications I could think of included 1) making the opening to the septic tank easier to get at 2) getting the waste to the tank without the use of flush toilets 3) actively managing the balance and decomposition inside the septic tank.

Collecting – You can invest in easy to use composting toilet systems. You can also get the job done just as well with some 5 gallon buckets. All you really need is something to hold the waste, that’s easy to carry and empty, and is cleanable with a bleach/water solution. I know Sheperd Survival calls them Honey Buckets, and their lids look like toilet seats. Having at least 4 buckets seems the best for a family, 2 in use collecting and 2 being emptied/cleaned. Toilet paper could be tossed in with such collections, alternately a cloth wipe system using scrap flannel and terry cloth could be used. I like wetbags for collecting used cloth wipes, made with a Polyurathane coated fabric (PUL); zippers and velcro hangers help keep the bag tidy. The collected humanure will need to compost for a couple of years. Most of the humanure guidebooks I’ve read recommend a 3 pile system. One pile being added to, one pile composting, and one pile being used as fertilizer.

Keeping the smell down – In the collecting buckets, sawdust does a good job of balancing the carbon to nitrogen ratio and keeping things under control. A good rule of thumb is to cover it until it doesn’t smell anymore. More sawdust can be used in the larger piles outside. Leaves, kitchen wastes and straw can also be used. Keeping the compost moist will aid in break down and smell free enjoyment. Be heavy handed with the cover material. Put a good base of it at the bottom and around all sides of the pile. Let it compost for plenty of time, it will look and smell like nice soil when it’s done composting, don’t be tempted to put half-finished compost on your garden. Even finished, be mindful about when and where you apply humanure compost. Improperly done, composting humanure can be a vector for disease transmission.